From 91c960b0056672e74627776655c926388350fa30 Mon Sep 17 00:00:00 2001 From: Brendan Jackman Date: Thu, 14 Jan 2021 18:17:44 +0000 Subject: bpf: Rename BPF_XADD and prepare to encode other atomics in .imm A subsequent patch will add additional atomic operations. These new operations will use the same opcode field as the existing XADD, with the immediate discriminating different operations. In preparation, rename the instruction mode BPF_ATOMIC and start calling the zero immediate BPF_ADD. This is possible (doesn't break existing valid BPF progs) because the immediate field is currently reserved MBZ and BPF_ADD is zero. All uses are removed from the tree but the BPF_XADD definition is kept around to avoid breaking builds for people including kernel headers. Signed-off-by: Brendan Jackman Signed-off-by: Alexei Starovoitov Acked-by: Björn Töpel Link: https://lore.kernel.org/bpf/20210114181751.768687-5-jackmanb@google.com --- tools/include/linux/filter.h | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'tools/include/linux') diff --git a/tools/include/linux/filter.h b/tools/include/linux/filter.h index ca28b6ab8db7..e870c9039f0d 100644 --- a/tools/include/linux/filter.h +++ b/tools/include/linux/filter.h @@ -169,15 +169,22 @@ .off = OFF, \ .imm = 0 }) -/* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */ +/* + * Atomic operations: + * + * BPF_ADD *(uint *) (dst_reg + off16) += src_reg + */ -#define BPF_STX_XADD(SIZE, DST, SRC, OFF) \ +#define BPF_ATOMIC_OP(SIZE, OP, DST, SRC, OFF) \ ((struct bpf_insn) { \ - .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \ + .code = BPF_STX | BPF_SIZE(SIZE) | BPF_ATOMIC, \ .dst_reg = DST, \ .src_reg = SRC, \ .off = OFF, \ - .imm = 0 }) + .imm = OP }) + +/* Legacy alias */ +#define BPF_STX_XADD(SIZE, DST, SRC, OFF) BPF_ATOMIC_OP(SIZE, BPF_ADD, DST, SRC, OFF) /* Memory store, *(uint *) (dst_reg + off16) = imm32 */ -- cgit v1.2.3